U.S. patent application number 09/805956 was filed with the patent office on 2002-10-31 for method of simulating nozzle spray interaction with fire, smoke and other aerosols and gases.
Invention is credited to Ebersole, John Franklin JR., Furlong, Todd Joseph.
Application Number | 20020160343 09/805956 |
Document ID | / |
Family ID | 26885273 |
Filed Date | 2002-10-31 |
United States Patent
Application |
20020160343 |
Kind Code |
A1 |
Ebersole, John Franklin JR. ;
et al. |
October 31, 2002 |
Method of simulating nozzle spray interaction with fire, smoke and
other aerosols and gases
Abstract
A method is presented for calculating a force to apply to
components in a computer simulation to simulate the effect that an
extinguishing agent stream (e.g., water or foam from a nozzle)
should have on airflow in the vicinity of the stream, thereby
affecting the movement of other components of the simulation. The
method is designed to work in real-time as part of a virtual
reality, augmented reality, or other real-time 3-D graphics
simulation. In addition to the preferred embodiment of calculating
forces to apply to a fire and smoke plume, the invention also
contemplates calculation of a force to apply to aerosols and
particles that are not part of a fire and smoke plume.
Inventors: |
Ebersole, John Franklin JR.;
(Bedford, NH) ; Furlong, Todd Joseph; (Goffstown,
NH) |
Correspondence
Address: |
Mirick O'Connell DeMallie & Lougee, LLP
100 Front Street, Suite 1700
Worcester
MA
01608-1477
US
|
Family ID: |
26885273 |
Appl. No.: |
09/805956 |
Filed: |
March 14, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60189548 |
Mar 15, 2000 |
|
|
|
Current U.S.
Class: |
434/226 |
Current CPC
Class: |
G09B 23/06 20130101 |
Class at
Publication: |
434/226 |
International
Class: |
G09B 019/00 |
Goverment Interests
[0003] This invention was made with Government support under
Contract Number N61339-98-C-0036 awarded by the Department of the
Navy. The Government has certain rights in the invention.
Claims
What is claimed is:
1. A method of calculating in real-time a force to apply to
components in a computer simulation to simulate the effects that an
extinguishing agent stream has on the airflow in the vicinity of
the stream.
2. The method of claim 1 wherein the said simulation components are
selected from the group of simulations consisting of fire plumes,
smoke plumes, ambient steam, ambient smoke, fumes, other aerosols,
gases, and particulate matter.
3. The method of claim 1 where the said computer simulation
components are particle systems.
4. The method of claim 1 where a particle system is used to
simulate the extinguishing agent.
5. The method of claim 1 where multiple layers of cones of
extinguishing agent are used to simulate multiple levels of force
to apply to the simulation components.
6. The method of claim 5 where the applied force varies from cone
layer to cone layer in order to accelerate the components of the
simulation towards the velocity of the extinguishing agent stream
in the cone layer.
7. The method of claim 4 where the extinguishing agent particle
mass, type, particle velocity, and distance from extinguishing
agent particles to other particles are used to determine a force to
apply to simulation components.
8. The method of claim 1 where the results of the calculations are
used to graphically simulate the effects of the extinguishing agent
stream on the components of the simulation.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of pending Provisional
patent application No. 60/189,548 filed Mar. 15, 2000.
[0002] This application is related to pending patent application
Ser. No. 09/525,983 filed Mar. 13, 2000.
FIELD OF THE INVENTION
[0004] This invention relates to simulating use of nozzle spray to
combat hazardous conditions in emergency situations, such as when
performing firefighting, with real-time computer graphics,
including the use of particle systems.
COPYRIGHT INFORMATION
[0005] A portion of the disclosure of this patent document contains
material that is subject to copyright protection. The copyright
owner has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure as it appears in the
Patent and Trademark Office records but otherwise reserves all
copyright works whatsoever.
BACKGROUND OF THE INVENTION
[0006] In a simulation, flow from a nozzle should affect airflow in
an environment and cause motion of aerosols and gases to be
affected. In the preferred embodiment of this invention, a
firefighter training simulation, extinguishing agent flow from a
nozzle should affect the path of a fire and smoke plume. This
invention simulates such an effect with considerably less
computational cost than a computational fluid dynamics (CFD)
simulation, allowing for real-time simulation. This invention also
applies to graphical components other than fire and smoke,
including ambient steam, ambient smoke, visible fumes, invisible
fumes, and other aerosols, gases, and particulate matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a diagram indicating a nozzle, extinguishing agent
stream, and fire and smoke plume.
[0008] FIG. 2 is a diagram is a variant of FIG. 1 where the
extinguishing agent stream is modeled to have multiple cone layers
to represent multiple velocities in the profile of the stream.
DETAILED DESCRIPTION OF THE INVENTION
[0009] FIG. 1 represents the preferred embodiment of a real-time
graphical simulation of an extinguishing agent 1 (e.g., water or
foam) exiting a nozzle 2 in the vicinity of a fire and smoke plume
3. If the extinguishing agent, fire, and smoke plume are modeled as
particle systems, each extinguishing agent, fire, or smoke particle
will have a mass and a velocity associated with it. Using a scale
factor based on distance, a force on the fire and smoke particles
can be calculated from the speed and direction of extinguishing
agent particles. To model the effect, an equation of the form
(other actual forms are envisioned, but they will mainly show
similar characteristics): 1 PV Out = PV In + ( ExtAV - PV In 1 + R
) * K
[0010] can be made, where:
[0011] PV.sub.out is the velocity (3-D vector) of the smoke and
fire particles after the force is applied
[0012] PV.sub.in is the velocity (3-D vector) of the smoke and fire
particles before the force is applied
[0013] ExtAV is the velocity (3-D vector) of extinguishing agent
particles
[0014] R is the radial distance between the smoke and fire
particles and the extinguishing agent particles
[0015] K is a factor that can be adjusted (from a nominal value of
1) for:
[0016] Desired friction of the particle interactions
[0017] The time in between simulation updates (will be referred to
as .DELTA.t)
[0018] Mass of the smoke, fire, and extinguishing agent
particles
[0019] Or other particular simulation characteristics where a value
of 1 produces unrealistic results
[0020] A force on the fire and smoke particles can be calculated
based on the change in velocity: 2 F = ( PV out - PV in ) ( Mass )
t
[0021] where:
[0022] F is the actual force (3-D vector) to be applied to the
smoke and fire particles
[0023] Mass is the mass of the fire or smoke particles
[0024] .DELTA.t is the time in between simulation updates
[0025] Taking the above two equations, substituting and
simplifying, the equation for the calculated force could be: 3 F =
( ExtAV - PV In 1 + R ) * K * Mass t
[0026] Other versions of this equation are envisioned, but they are
expected to be of a similar nature, with the same inputs as this
equation.
[0027] The application of the calculated force simulates the visual
effect of the extinguishing agent stream causing airflow that
alters the motion of fire and smoke particles. Additionally, the
calculations can be applied to smoke or other particles that are
not part of a fire and smoke plume, such as extinguishing agent
passing through ambient steam or ambient smoke particles in a room.
The invention extends to other aerosols, gases, and particulate
matter, such as dust, chemical smoke, and fumes.
[0028] As shown in FIG. 2, a side view of the preferred embodiment,
a further refinement for determining a force to apply to particles
in the fire and smoke plume 3 would entail modeling extinguishing
agent 1 in cones 1a, 1b, and 1c (which are affected by gravity and
will droop) from the nozzle 2, where the multiple additional
concentric cones 1b and 1c to apply varying force. One embodiment
that can produce the cones 1a, 1b, and 1c can be a system of rings
(the system of rings may be modeled as a particle system) emitted
from the nozzle, which, when connected, form cones 1a, 1b, and 1c.
Those fire and smoke particles 3a which are contained mostly inside
the inner cone 1a of the extinguishing agent 1 can have one level
of force applied, and fire and smoke particles 3a which are not
contained within cone 1a, but are contained within cones 1b or 1c
can have a different, often smaller, force applied to them. Thus,
multiple levels of velocity from extinguishing agent and air
entrainment can be easily simulated to apply multiple levels of
force to the fire and smoke. The additional cones 1b and 1c (or
more if additional levels of force are desired) do not have to be
drawn in the simulation, as they could be used strictly in
determining the force to apply to the fire and smoke.
[0029] In the case of modeling the extinguishing agent as
concentric cones outlined above, the force applied to a particle
can be modeled as: (A) the extinguishing agent cone(s) 1a, 1b, 1c
each having a velocity associated with them, (B) a difference in
velocity between a particle 3a and the extinguishing agent cone(s)
1a, 1b, 1c can be calculated, (C) a force can be calculated that
scales with that difference, and (D) the particles 3a will
accelerate based on the force calculated, approaching the velocity
of the extinguishing agent inside of the cone(s) 1a, 1b, 1c.
[0030] The results of the simulated effects described above can be
observed by drawing particles as computer-generated graphics
primitives using real-time graphics software and hardware. The
invention is applicable to such areas as training simulations and
computer games.
[0031] Although specific features of the invention are shown in the
drawing and not others, this is for convenience only, as each
feature may be combined with any or all of the other features in
accordance with the invention.
[0032] Other embodiments will occur to those skilled in the art are
within the following claims.
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